You'd never know it by looking at the sea of starlets decked out in couture gowns at the SAG Awards, but there was something different about Beanie Feldstein's dress.

The 24-year-old "Lady Bird" star told The Cut in an interview that she wore her high school prom dress to one of Hollywood's biggest nights.

"I put it on and it fit, surprisingly maybe better than it did in high school!" Feldstein told The Cut's Anna Silman of her black Kay Unger gown, adding that her mom and best friend then told her she had to wear it to the show.

The prom dress was a fitting wardrobe choice, Feldstein said, because of her "Lady Bird" character's arc, which also ends at a prom in the film.